1 /* $NetBSD: lib_sw_fence.c,v 1.2 2021/12/18 23:45:31 riastradh Exp $ */
2
3 /*
4 * Copyright © 2017 Intel Corporation
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice (including the next
14 * paragraph) shall be included in all copies or substantial portions of the
15 * Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
22 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
23 * IN THE SOFTWARE.
24 *
25 */
26
27 #include <sys/cdefs.h>
28 __KERNEL_RCSID(0, "$NetBSD: lib_sw_fence.c,v 1.2 2021/12/18 23:45:31 riastradh Exp $");
29
30 #include "lib_sw_fence.h"
31
32 /* Small library of different fence types useful for writing tests */
33
34 static int __i915_sw_fence_call
nop_fence_notify(struct i915_sw_fence * fence,enum i915_sw_fence_notify state)35 nop_fence_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
36 {
37 return NOTIFY_DONE;
38 }
39
__onstack_fence_init(struct i915_sw_fence * fence,const char * name,struct lock_class_key * key)40 void __onstack_fence_init(struct i915_sw_fence *fence,
41 const char *name,
42 struct lock_class_key *key)
43 {
44 debug_fence_init_onstack(fence);
45
46 __init_waitqueue_head(&fence->wait, name, key);
47 atomic_set(&fence->pending, 1);
48 fence->error = 0;
49 fence->flags = (unsigned long)nop_fence_notify;
50 }
51
onstack_fence_fini(struct i915_sw_fence * fence)52 void onstack_fence_fini(struct i915_sw_fence *fence)
53 {
54 if (!fence->flags)
55 return;
56
57 i915_sw_fence_commit(fence);
58 i915_sw_fence_fini(fence);
59 }
60
timed_fence_wake(struct timer_list * t)61 static void timed_fence_wake(struct timer_list *t)
62 {
63 struct timed_fence *tf = from_timer(tf, t, timer);
64
65 i915_sw_fence_commit(&tf->fence);
66 }
67
timed_fence_init(struct timed_fence * tf,unsigned long expires)68 void timed_fence_init(struct timed_fence *tf, unsigned long expires)
69 {
70 onstack_fence_init(&tf->fence);
71
72 timer_setup_on_stack(&tf->timer, timed_fence_wake, 0);
73
74 if (time_after(expires, jiffies))
75 mod_timer(&tf->timer, expires);
76 else
77 i915_sw_fence_commit(&tf->fence);
78 }
79
timed_fence_fini(struct timed_fence * tf)80 void timed_fence_fini(struct timed_fence *tf)
81 {
82 if (del_timer_sync(&tf->timer))
83 i915_sw_fence_commit(&tf->fence);
84
85 destroy_timer_on_stack(&tf->timer);
86 i915_sw_fence_fini(&tf->fence);
87 }
88
89 struct heap_fence {
90 struct i915_sw_fence fence;
91 union {
92 struct kref ref;
93 struct rcu_head rcu;
94 };
95 };
96
97 static int __i915_sw_fence_call
heap_fence_notify(struct i915_sw_fence * fence,enum i915_sw_fence_notify state)98 heap_fence_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
99 {
100 struct heap_fence *h = container_of(fence, typeof(*h), fence);
101
102 switch (state) {
103 case FENCE_COMPLETE:
104 break;
105
106 case FENCE_FREE:
107 heap_fence_put(&h->fence);
108 }
109
110 return NOTIFY_DONE;
111 }
112
heap_fence_create(gfp_t gfp)113 struct i915_sw_fence *heap_fence_create(gfp_t gfp)
114 {
115 struct heap_fence *h;
116
117 h = kmalloc(sizeof(*h), gfp);
118 if (!h)
119 return NULL;
120
121 i915_sw_fence_init(&h->fence, heap_fence_notify);
122 refcount_set(&h->ref.refcount, 2);
123
124 return &h->fence;
125 }
126
heap_fence_release(struct kref * ref)127 static void heap_fence_release(struct kref *ref)
128 {
129 struct heap_fence *h = container_of(ref, typeof(*h), ref);
130
131 i915_sw_fence_fini(&h->fence);
132
133 kfree_rcu(h, rcu);
134 }
135
heap_fence_put(struct i915_sw_fence * fence)136 void heap_fence_put(struct i915_sw_fence *fence)
137 {
138 struct heap_fence *h = container_of(fence, typeof(*h), fence);
139
140 kref_put(&h->ref, heap_fence_release);
141 }
142